Conventional electronic memories may be implemented by arrays of discrete memory cells. Many types of memory cells and many systems for writing a value to and reading a value from a memory cell currently exist.
FIG. 1 shows a cross-sectional view of floating-body dynamic random access memory (FBDRAM) memory cell 1. Cell 1 comprises a single transistor and is known as a gain cell because a value may be stored within and read from the transistor. The transistor is fabricated upon oxide 2 in a silicon-on-insulator (SOI) arrangement. The transistor includes n-type source region 3, p-type body region 4 and n-type drain region 5. Oxide 6 is disposed over gate region 4 and conductive element 7 overlays oxide 6.
A value is stored and read by manipulating charge carriers within body region 4. To improve charge retention, body region 4 may be isolated from adjacent memory cells by oxide 6, by the pn junctions between itself, source region 3 and drain region 5, and by shallow trench isolation in front of and behind the plane of FIG. 1. SOI process technology may, however, be undesirable in some instances.